[ubuntu] ubuntu doesn't run after upgrade to 12.04

view story

http://ubuntuforums.org – I had ubuntu 10 installed then I upgraded to 11 with no problem. And then I saw the upgrade to 12.04 button on update manager. During the upgrade it gave me countless errors but installation continued nevertheless. Now when I restart the screen keeps on the ubuntu loading screen and when I press escape its at the line "stopping CUPS printing spooler/server" and the status is ok but in previous line starting cups has failed so has the starting modem connection manager. What can I do from the grub commandline to fix this problem? (Hardware)